There is and continues to be encountered an ever-increasing, voluminous demand for "ersatz" or substitute wood-based, conventional plastic(s) and/or thereof-derived products for utilization in place of boards, sheets and other cuttings and constructional sizings of normally-sawn or usually-milled lumber and various sorts of timber wood stock(s) as well as variously-shaped and -fabricated articles of plastic(s) materials. The same applies to many other forms and end-use preparations of large numbers of goods and products other than those that are structural building, insulation, sound-proofing and the like purposes. Free- and irregular-form configurations useful and/or needed for many purposes are includable in the latter types of oftentimes rather important manufactures.
This, as it now has been for many decades, remains so as to such modernly-common products as plywood, composite board (of either a standard grade which is not particularly intended or adapted for outdoor or exterior usages or the so-called "tempered" board which has marked water- and/or moisture-resistance and is frequently employed where resistance to the damp and weatherability are factors influencing its durability and attractiveness for being selected to use). Light-weight insulating, sound-deadening materials for covered, over-laid or otherwise sheathed and enclosed building arrangements fall within the broad range of such products. The same applies to those insulating, sound-damping and/or other structurally-functional materials are made with decorative and appealing surface features and appearances to adapt them for exposed installation whether in indoor or outdoor, or both, situations of application.
The product known and commercially-available as "MASONITE" {Reg. TM} is an excellent example of high quality, high strength and well-dimensioned composite hardboard which finds wide usage in replacement of typical lumber for constructional purposes; generally at least meeting and frequently exceeding the qualities of equivalent and/or replaceable conventionally-milled timber stock (viz., that sawed into beams, planks, boards, etc., of convenient sizes) insofar as concerns its characteristics and properties as a material of construction. Notwithstanding, "MASONITE" does tend to be a relatively-heavy product with a density that usually is at least that of natural wood. Another good synthetic structural building board product (generally of a much lighter nature than is "MASONITE") is that commercially-available under the Trade-Designation "Super 440" which is obtainable from the HOMASOTE COMPANY of West Trenton, N.J. 08628.
Thus and co-relative with the foregoing, there is being acutely-experienced a growing requirement and more pressing demand for low-bulk and light-weight products imbued with the indicated characteristics and, especially in connection therewith, wherein the same also insulate excellent thermal insulating properties.
Good evidence of this is to be found as a well-established thing in and from such a prestigious Reference Source as the Kirk-Othmer Publication (more-fully cited infra) in Volume 13 thereof at Page 597. Another indication of more recent analogous import is to be found in CZECHOSLOVAK Patent No.: CS 192,139 dated Jan. 31, 1982.
The above-indicated capabilities in goods and products of the mentioned characterization is not only of great interest for the fabrication of pre-formed board- and slab-like structures (such as in "MASONITE", "Super 440" and their likes and equivalents), but in and for compositions and resulting constructions therefrom that are more-or-less freely-formable, without the scope of conventional molding, pressing and calendaring operations, by hand or with the aid of spatula-like implements, trowels (including those of the varieties known as: "garden"; "curbing"; "corner"--especially "outside corner"; "guttering"; "pointing"; "brick"; "plastering"; "circle" or "inside cove"; and "radius"), knives and scalpels or other knife-like devices; scrapers or "chasers" and the like; pottery-forming implements and elements; and so on and so forth.
Some good evidence of what is currently-occurring during the present time period to drastically-escalate the costs and prices of normal, natureal lumber goods and derivatives thereof such as paper products (including coarse papers, carboards, etc.) therefrom, at least in the UNITED STATES OF AMERICA, is revealed and somewhat spelled out in the Article entitled "TROUBLE IN TIMBER COUNTRY" which occurs at Pages 30-32, inclusive, of the Dec. 13, 1982 Edition of INDUSTRY WEEK.
At least for newsprint recycling and analogous paper product manufactures (including cardboards) from reconstituted goods, a noticeable increase in paper and cardboard recovery activities for the purpose has been seriously undertaken. This is evident even in such parochial and provincial reports thereabout as appeared at Page A6 of the Publication entitled SAGINAW COUNTY (MICHIGAN) WEEKLY, a local Newspaper, which appeared thereat in the Tuesday, Nov. 19, 1982 Edition thereof in an Article entitled "Group Creating Jobs Out Of Ordinary Trash".
The use, additionally of waste paper (especially of the "coarse grade" as hereinafter more fully characterized) and/or cardboard and or sawdust as a fill for various adhesively-bound--including usages of plastics materials to contain and provide cohesion for the filler--or otherwise integrated products in which the indicated materials are substituted for other possible filling constituents seems, at least on-hand, to consitute logical possibiliy(ies) for getting at and pragmatically circumventing the indicated problems. In fact, a fair amount of work has been done and activity expended along this line.
There are, however, several significant and deleterious difficulties and drawbacks involved in heretofore-known attempts to product wooden-like or resembling articles from waste paper, cardboard and so forth, as well as from sawdust, especially as those commodities perforce have been utilized in prior practice. These include the facts and circumstances that:
(1). Coarse paper goods, including such items as newsprint, kraft paper, cardboard and so forth and whether or not in virgin and as manufactured or waste form(s) are not particularly amenable in any normally-as-obtained condition and structure to be directly utilized as a filler or loading material for incorporation into and integration by and with typical and conventional sorts and varieties of resin and/or plastic(s) binder systems and the like. This, of course, contemplates obviously different treatment and reconstitution of waste paper, etc., in conventional "recycle" reclamation procedures in which the waste paper is simply used to replace or extend fresh wood or other vegetable fiber pulp or stock in a more-or-less standard paper-making procedure. For resin-binding applications, however, waste paper and the like is extremely difficult to handle and mix--even with intensive-mixing apparatus--with binder systems whether or not the paper stock is used directly-as-is in normally-flat and usually rather-thinly planar sheet- or web-like form(s); this being so even when the coarse paper stock is shredded or otherwise comminutated (as, for example, to be subdivided and size-reduced by shredding, cutting, confetti-making and equivalent or analogous techniques into strips, squares, circles, etc.) or, as may be attempted, crumpled or subjected to the like sort of physical distortion and form-transfer(s) of the sheet stock for material handling purposes. In other words, there is typically and ordinarily no easy achievement of interblending paper goods (excepting for true laminate constructions) into homogenous and uniform masses with most common binding agents. The relative "dryness" or parched condition of most coarse paper stock also adds to the complexity and difficult of this, as can be readily appreciated. Along this line, the moisture content of most coarse paper goods usually lies in the 7 or 8 to 10-12 percent of actual (taken on total weight) moisture (i.e., water) content range; with something on the order of 9 or so %, by way of illustration, being common for the usual either fresh or waste newsprint(s).
(1'). Explicitly more specifically-informative of the immediate foregoing in connection with paper(s), its (and their) manufactures, and the recycling thereof additional reference may be had to said Kirk-Othmer Publication (cited completely infra) in: Volume 16, Pages 768-770 and 773, inclusive; Volume 19, Pages 392, 395-397, 408, 409, 416 and 417, inclusive; and Volume 19, Pages 941 and 986-991, inclusive thereof.
(2). As to situations wherein sawdust (or equivalent comminuted cellulosic) particles are employed--which typically and usually, despite the fact that exceptions to and variances from the indicated normality, have and are of particulated dimensional characteristics which are on an average particle size reckoning that is ordinarily not much if any more than the No. 10 Size, advantageously less than the No. 12 Size, in the U.S. SIEVE SERIES--must be dried prior to the previously-developed utilizations thereof so as to have an already-standardized and -established maximum moisture content that is between about 3 and about 15 weight percent (i.e., "wt. %"). Now then, "wet" sawdust and the bulk of its equivalent comminuted cellulosic natural plant or "vegetable" counterparts as from undried tree cuttings and other sources (depending on particular species taken and, to some extent, involved location and Season of the taking) has a natural moisture content of from about 40 to about 100 wt. %; a fair average for this being in the neighborhood of 60-70 wt. %. In this connection, the indicated wt. % ranges must be understood and accepted in accordance with the common terminology and definition applied in the trade for given moisture content in such materials. Accordingly and as regards at least "wet" sawdust, the 100% moisture content level is one which, when equated to an absolute relative constituent parts by weight (i.e., "pbw") basis, means 100 parts of the sawdust and its associated contents as contained in the wood wherefrom it is obtained and 100 pbw water. In other words, the moisture content given is based on that percentage of water in the composition based on and compared to the content of the remaining non-aqueous content(s) of the wood (or the like) from which a given "wet" sawdust lot has been obtained. It is thus readily deducible that (by kiln-drying or the like oven-heating procedures), in order to prepare conventionally-suitable, Specification(s)-meeting, filler-grade sawdust, it is necessary to remove from the "wet" sawdust anywhere from about 97 wt. %, as a maximum, to 35 wt. %, as a minimum, of the original water content of the "wet" starting material to be converted into or incorporated in some sort of desired product. The heat energy required for such water ridding of and from the "wet" sawdust or the like is, quite obviously, enormous; with the expense of same, especially under current conditions and factors of cost for typically-employed fuels, tending to attach almost prohibitive aspects thereabout and thereto.
(3). Binding of dried sawdust and the like wood- or other vegetable-based filler has only heretofore been with relatively expensive and more or less complex and technically-demanding binder systems, including plastic or resin binders. In illustration of this, reference may be had to the complicated and not uncostly nor uneasy technology involved for such purposes as is disclosed, inter alia, in U.S. Pat. Nos.: 1,642,846; 2,645,587; 2,851,730; 3,309,444; 3,391,038; 3,493,527; 3,554,941; 3,560,255; 3,649,442; 3,787,344; 3,790,401; 3,806,562; 3,956,541; and 4,165,409. As a basically-different curiosity (for present purposes) relating to lightweight brick of clay, sawdust and mortar, see the excerpt identified as "Fin-Times 12-1718, Page 11, CKAR" which appears at Page 12 of the "TECHNICAL SURVEY" for Dec. 23, 1978. Note also Page 1,548 of the "RUBBER HANDBOOK" (40th Ed.). A recent typical illustration of the state of the art involved in the binding into fabricated shaped articles of cellulosic materials is to be found in the March 1982 Issue (at Page 82 thereof) of the INTERNATIONAL HARVESTER News (a House Organ known as "THE FURROW") which describes the use of dyed straw pressed together into decorative useful objects using resin for the cohesively-binding purpose. Another somewhat-remote state-of-art Article of iterest is entitled "Corn Starch: A Low-cost Route To Novolac Resins" by John P. Mudde appearing at Page 69 of "MODERN PLASTICS" for February 1980.
(4). Further to the sort of art mentioned in the above Item (3), reference may be had to the rather comprehensive explanation of various particulated wood products to be found in the 3rd Edition (as well as in earlier complications) of the aforesaid famous Kirk-Othmer "ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY" published by John Wiley & Sons, Inc. of New York City. This authoritative source provides definitions of hardboard, particle board, "MASONITE" (Reg. TM), insulating board, the so-called dry process board, composition board and so on and so forth; including good descriptions of the method(s) of their respective manufacture--all of which depend more or less on the inclusion and effect for binding of various synthetic resin adhesives. It is noteworthy to observe at Page 377 of Volume 22 of said 3rd Edition the expression as a generality that "wood is seldom used where resistance to chlorine and hypochlorite solution is required".
(5). Additional art of interest illustrating plainly contrastive and diverse techniques for the surface adhesion of and between veneers and/or equivalent layers of pre-formed and already-dried wood and/or wood-based structures (whether or not prepared from particulated starting materials) may be found in U.S. Pat. Nos.: 4,007,312 and 4,183,997 which depend for the already-shaped article surface cohesion effect primarily on employment of certain catalysts and conduction of the procedure under generally non-alkaline (or, at least, not pronouncedly alkaline) conditions for the particularized laminating operation which is not adapted to bind together for fabrication into desired structural forms any comminutated and "wet" starting cellulosic materials.
(6). Other art, remotely involved, having no particular bearing on the binding of coarse paper whether or not extended with "wet" sawdust, per se, and/or its comminuted raw cellulosic likes and equivalents in undried or substantially undried condition and form (e.g., meaning with respect to the latter that most if not all of the natural water in the "wet" sawdust, etc., particles being treated remains there at the beginning of the integrally-bonding fabricating procedure) includes U.S. Pat. Nos.: 2,187,016; 2,676,884, 3,536,578 (dealing, by way of particularization, with the addition of an oxidizing agent not reactive with starch to a paperboard material which is sized with starch); 3,859,108; 4,107,379; and 4,234,658 (the last-identified, for example, dealing with the bonding of subdivided wood or bark (somewhat analogous to wood, etc., pulp for paper) with an adhesive made up of ground-up foliage that has been treated with formaldehyde).
(7). Additionally, the prior art (besides requiring, as has been noted, use of dried sawdust or the like) has almost invariably aimed itself at the capability and desideration of providing: "super"-(as it were)-type goods having high-quality and literally impeccable characteristics as an essential; very good finish and tolerance potential(s); and high strength in the finished, fabricated sawdust and the like or at least analogous particles which are bonded together into composites (such, by way of repeated illustration, as the well-known and already-referred-to phenol-formaldehyde and/or urea-formaldehyde resin-bonded chip and/or particle board and similar manufactures that have gained widespread acceptability and usage in the market).
Despite all above-mentioned and additional which is utilized in and/or known to the art, the possibility of direct usage of coarse paper and/or its likes or equivalents for answer(s) to and solution(s) of the indicated problems appears to have been inadequately addressed and not satisfactorily resolved. This seems to be the case notwithstanding the enigmatic fact that there is a literal super-abundance of coarse paper goods, as well as "wet" sawdust and the like or equivalent fibrous plant cellulosic materials in current available and largely non-utilized supply. In many locations, waste newsprint, kraft paper and cardboard as well as "wet" sawdust and/or its suitable alternatives can be had for no or little more than handling and/or shipping charges; being unfortunately (and distressingly to possessors thereof) in not great demand. Furthermore and of increasingly significant moment insofar as concerns waste paper and such things as "wet" sawdust and the like utilization or beneficial disposal or application, environmental restrictions in many locales now prevent burning for fuel purposes (especially on an industrial basis) of such materials.
And, along with these deficiencies, lacks and draw-backs nothing in applicable prior art appears to realistically concern itself with nor suggest, teach, lead to or provide the instantly-contemplated, unique and estimable compositions and products derived and produced directly from coarse paper or the like in the way so crucially direct and indigenously advantageous as in the present contribution to and advance in the art.